Those that know me know that I love my iPod. They probably also know that I avoid iTunes - I think it's a reasonable application, just not ideal for me. However, if you are an iTunes user then you may be aware of the announcement that version 4.9 will support podcast subscriptions.
If you can't wait that long then check out BadApple. It's a plugin for iTunes that does what 4.9 promises right now. Looks nice but I haven't used it - caveat empor! Oh, BTW it's Windows-only.
Personally, I'll continue to use Doppler. It's not perfect but it does the job.